The disclosures herein relate generally to building structures and more particularly to lifting devices used in the building of structures.
It is well known that building structures and more specifically domed structures, are built using the assistance of a crane or lifting device which is centrally mounted relative to the dome to be constructed. The dome is built radially outwardly from the crane.
The crane comprises a vertical tower of considerable height. A lifting member is movably mounted relative to the vertical tower. The lifting member is advanced upwardly toward the top of the tower by being pulled from above.
A plurality of cables extend radially outwardly from the lifting member. The cables attach to the dome which is built from the top down such that sections are added to the outer periphery of the dome. As each section is added, the dome is raised by the lifting member so that another section can be added to the periphery of the dome.
In this manner, the dome is formed outwardly and downwardly by sequentially adding sections to the outer periphery of the dome which may have a circular or non-circular periphery.
As a result, the vertical tower must be constructed in its entirety and the lifting member attached thereto, before any construction is begun.
Therefore, what is needed is a tower which can be built progressively as needed to accommodate the expanding size of the dome being constructed.
One embodiment, accordingly, provides a modularly constructed tower which is built in sections added to the base of the tower to accommodate the expanding height and girth of the dome. To this end, an apparatus for erecting a building structure includes a support base and a guide member mounted on the base. A lifting tower is elevatably mounted for movement on the guide member. The lifting tower is formed of sequentially added sections. A plurality of push-up devices alternately engage added sections of the lifting tower for elevating the lifting tower relative to the guide member. A portion of a building structure is formed of structural components. A suspension device is connected to the lifting tower and to the portion of the building structure for elevating the portion of the building structure in response to alternately actuating the push-up devices.
A principal advantage of this embodiment is that the tower does not need to stand at full height all of the time during construction. This minimizes exposure to wind loads, earthquakes, etc. The base provides stability to the lifting tower thus minimizing the need for extra foundations. The guide member provides stability and minimizes the need for extra guying. Also, there is no need to climb the structure or the tower during construction.